Chemistry Significant Figures Test - Summer 2019

How many significant figures are in 100 km? a. 1 b. 2 c. 3 d. Unable to determine

a. 1

Express 1,870,000 in scientific notation with the correct number of significant digits. a. 1.87 x 10^6 b. 1.87 x 10^6 c. 870 x 10^6 d. 870000 x 10^6

a. 1.87 x 10^6

A scientist obtains the number 0.0450067001 on a calculator. If the number actually should be recorded only to 4 significant figures, the number should read a. 0.4567 b. 0.04500 c. 0.0450067 d. 0.04501

d. 0.04501

The result of the following calculation would be written to correct number of significant digits as: 23.89 cm x 0.45 cm x 129.54 cm a. 1329.61977 cm^3 b. 1393 cm^3 c. 1390 cm^3 d. 1400 cm^3

d. 1400 cm^3

Consider the numbers 23.68 and 4.12. The sum of these numbers has ___ significant figures, and the product of these numbers has ___ significant figures. a. 3,3 b. 4 4 c. 3,4 d. 4,3

d. 4,3

The length measurement of 9.66 cm has three significant figures, two of which are certain from the ruler and one of which is a(n) _______.

estimate or guess

Zeros that act as _____ are not significant

placeholders

When you convert to ________ you remove the trailing place holding zeros.

scientific notation

The numbers that are reported in an answer to a calculation involving measurements are called ______.

significant

All final ____ to the right of the decimal place and to the right of a number are significant.

zeros

0.3827 g/ 45.2 mL =

0.00727 g/mL because 45.2 has three significant figures, compared to 0.3287 with four significant figures so the answer must have three.

(0.12 mm + 5.16 mm) x (45.56 mm - 18.903 mm) =

144 mm^2 because the operation is multiplication so, one must round to the smallest number of significant figures which is three.

125.5 kg + 52.689 kg =

178.2 kg because when adding, one must round to the least precise measurement, in this case, it's the tenths spot.

The number 0.000030070 expressed in exponential notation with the correct number of significant figures is a. 3.007 x 10^5 b. 3.007 x 10^-5 c. 3.0070 x 10^-5 d. 3.0070 x 10^5

3.00700 x 10^-5

(1250 cal) - (234.207 cal + 952.691 cal) =

63 cal because, according to the rules of addition/subtraction in this case, one must round to the least number of decimals of one of the measurements.

______ numbers are always significant.

Non-zero

Round off the following numbers to the number of significant figures indicated: Number # of Sig Figs Final Answer 0.58333333 four 451.0324 three 0.0090060 two 490,000.402 three 942.044072 six

Number # of Sig Figs Final Answer 0.58333333 four 0.5833 451.0324 three 451 0.0090060 two 0.0090 490,000.402 three 4.90 x 10^5 942.044072 six 942.044

Zeros are always considered significant figures when they a. function as place holders b. occur between two nonzero numbers c. precede a decimal point d. both a and b

b. occur between two nonzero numbers

If you were required to round 0.06295 seconds to three significant figures, you would record as a. 0.06 b. 0.0629 c. 0.0630 d. 0.06295

c. 0.0630

The answer to the following problem would have how many significant figures? 52.8 m + 3.0025 m __________________________ 253.4 seconds a. 5 b. 4 c. 3 d. 2

c. 3

The measurement 0.00970810 km has how many significant figures? a. 4 b. 5 c. 6 d. 7 e. 8

c. 6

The second measurement of 12.56 gives three ______

certain values